Phytium Mailbox Driver
======================

The Phytium mailbox controller that has a channel/link to communicate
with the remote end. A link raises interrupt for any received data. However,
there is no specified way of knowing if the sent data has been read by the
remote. This driver assumes the sender polls STAT register and the remote
clears it after having read the data.

Mailbox Device Node:
====================

Required properties:
--------------------
- compatible:		Shall be "phytium,mbox"
- reg:			Contains the mailbox register address range (base
			address and length)
- #mbox-cells		Shall be 1 - the index of the channel needed.
- interrupts:		Contains the interrupt information corresponding to
			the link.

Example:
--------

mbox: mailbox@2a000000 {
	compatible = "phytium,mbox";
	reg = <0x0 0x2a000000 0x0 0x1000>;
	#mbox-cells = <1>;
	interrupts = <0 48 4>;
	clocks = <&sycclk>;
	clock-names = "apb_pclk";
};
